\mode<presentation>

\defbeamertemplate*{frametitle}{ess}[1][]
{
  \begin{beamercolorbox}[wd=\paperwidth, ht=1.2cm]{frametitle}
    \begin{tikzpicture}
      \useasboundingbox[fill=white] (0,0) rectangle(\the\paperwidth, 1.2);
      \fill[essblue] (0,0) rectangle(\the\paperwidth, 1.2);
      \ifx\insertframesubtitle\@empty%
      {\node[anchor=west, white, font=\Large] at (0,0.6){\insertframetitle};}
      \else
      {\node[anchor=west, white, font=\Large] at (0.0, 0.81){\insertframetitle};
        \node[anchor=west, white, font=\small] at (0.0, 0.35){\insertframesubtitle};}
      \fi
    \end{tikzpicture}
    
  \end{beamercolorbox}
}

\defbeamertemplate*{navigation symbols}{ess}
{
  \hbox{
%    \hbox{\insertslidenavigationsymbol}
%    \hbox{\insertframenavigationsymbol}
    \hbox{\insertsectionnavigationsymbol}
%    \hbox{\insertsubsectionnavigationsymbol}
%    \hbox{\insertbackfindforwardnavigationsymbol}
  }
}

% no navigation symbols in handout and trans mode:
\only<handout | trans>{\setbeamertemplate{navigation symbols}{}}

\mode<all>